High Streamflow Advisory for South Coast - October 13, 2016

Posted on October 12, 2016

High Streamflow Advisory: South Coast

What's a High Streamflow Advisory?A High Streamflow Advisory means that river levels are rising or expected to rise rapidly, but that no major flooding is expected. Minor flooding in low-lying areas is possible.

ISSUED: October 12 2016 3:00PM

The BC River Forecast Centre is issuing a High Streamflow Advisory for the South Coastincluding:

Howe Sound and Sea to Sky including the Squamish River, Stawamus River, Cheakamus River, Lillooet River and surrounding creeks and tributaries

North Shore Mountains including the Seymour River and surrounding creeks and tributaries

Fraser Valley including the Chilliwack River and surrounding creeks and tributaries

A series of Pacific storms are forecast to impact the BC coast over the next several days. The first system is expected overnight Wednesday and through Thursday, a second storm early Friday, and a third on Saturday. Heavy rainfall is expected with each storm and current forecasts from Environment Canada indicate the potential for 100 - 250mm or more of cumulative total precipitation across the South Coast from these three storms.

Rivers across the region are expected to rise rapidly on Thursday in response to rainfall, and remain elevated into the weekend, with increased flows likely as each of the remaining two systems move through. Current weather forecasts indicate that the storms will be of increasing intensity and severity from Thursday to Saturday. Specific details, including locations of highest rainfall intensity and the period of time between each storm, are important factors in determining flood risk during the upcoming storm period. These factors are expected to become clearer over the next few days. Hydrologic modelling based on current weather forecasts indicates the possibility of flood conditions over the Saturday to Sunday period. This outlook may change based on the ultimate track and rainfall patterns of each storm system.

The public is cautioned to stay clear of rivers during rain events due to quickly flowing water and potentially unstable riverbanks.

Current public weather alerts from Environment and Climate Change Canada can be found by following this link.

The River Forecast Centre will continue to monitor conditions and will provide updates as conditions warrant.